Heat Transfer Lab Reflection
Reflection: The Benefits of our Ice box design is that it is very small, compact and sturdy. In our Ice box design we had cotton ball to keep the ice from touching all surrounding surfaces. Our design was a 3 inch by 3 inch cube. On the inside of our ice box design, we had aluminum foil wrap around cardboard so that the freezing temperature is reflective back to the ice which would keep it cool and slow the melting rate. Our ice box is made up of cardboard, aluminum foil, and heavy construction paper. We use blue masking tape to keep it all together and to cover up any opening in our design. Before starting the Lab we measure the ice and the dimensions are 6cm long, 2cm wide and 2 1/2cm tall. After exactly one hour later the dimensions of the ice were 5 1/2cm long, 1 1/2cm wide and 2cm tall. The ice lost 36% percent of the ice and 64% percent was still intact on the ice. The downsides about our design was that we did not tape the top surface down to the box which might have let air from outside in the box which might have cause it to melt more. Another downside about our design is that we use a dark color to decorate our ice box which might have consume heat and might have increase the temperature inside of the box. We should have use a light color paper since in theory light colors absorb less heat from the sun.
Web Sources: Having light-colored containers or reflective container will help ice keep frozen because in theory, lighter colors and reflective surfaces absorb less radiation from the sun. This means that less quantity of heat would make the ice melt at a slower rate. In a experiment shows that aluminum foil will melt the melting rate compare to kitchen towels, or just plain ice. It showed that ice with aluminum foil did not melt until 2 hours. Since Aluminum foil is a insulator, the ice temperature will stay cool and the heat from the outside is reflective away from the ice box. The aluminum foil keeps the temperatures warm or freezing because it is a insulator. This is why my ice box perform the way it did because the aluminum foil slow the melting rate. http://lifestyle.iloveindia.com/lounge/how-to-prevent-ice-from-melting-6207.html http://www.all-science-fair-projects.com/print_project_1232_147 Heat and light are both different variations of energy. Light energy can be converted into heat energy. A black colored object absorbs all the wavelengths of light and converts them into heat which makes the object get warm. A White colored object reflects all the wavelengths of light so the light is not converted into heat and temperature of the object does not increase as much as a dark color object. Different colored wavelengths of light have different amount of energy. How light or how dark the object is affects the amount of heat absorb. A dark color object of a given color will absorb more photons than a light color object of the same color. This is why my ice box melted the ice more because our ice box had a black construction paper around the whole box. http://scienceline.ucsb.edu/getkey.php?key=3873 Cotton can be a good insulator because it slows down both convective and conductive heat loss. The cotton balls hold air in and around it fibers, but when cotton gets wet, the hollow fibers get fill with water and most of the insulation properties are lost. Cotton is a thermal insulator which means that it can keep objects warm or cool. This is why my ice box slow down the melting rate because the cottons ball were absorbing the ice temperature and it was keeping the ice box in cool temperature. http://www.ehow.com/facts_7624707_cotton-good-insulator.html |